I'm in the beginning stages of making plans for my next car, a classic caddy as a dd. I plan on swapping in a duramax, along with the brake system out of a caprice or something along those lines (whatever's the best bang for the buck). At any rate, I'm trying to spend 20 or less plus the proceeds of selling my Pontiac. And I'm not sure whether I'm best off going with completely refurbishing a beater, getting something in decent condition or going for a later model. After looking online it appears that you can get a rebuilt 390 for roughly $3,500. Could I expect this for an engine that hasn't been rebuilt but runs well? Also, how much can I expect to get for a transmission in very good condition? I was guessing $1,500, but obviously I have no idea.